1. Field of the Invention
The present invention relates to a method of developing a resist film formed on a substrate such as an LSI, a method of surface treatment of the resist film, a development processor for the resist, and a surface processor.
2. Related Art
The following publications show related art of the present invention.    (1) Patent Document 1; Japanese Patent Laid-Open Publication No. 07-284739 (1995)    (2) Patent Document 2; Japanese Patent Laid-Open Publication No. 09-139374 (1997).    (3) Patent Document 3; Japanese Patent Laid-Open Publication No. 11-87306 (1999)    (4) Patent Document 4; Japanese Patent Laid-Open Publication No. 2001-220828
In manufacturing a large-scale, high-integration density and high-performance device, a resist film, which is formed on a silicon wafer is exposed, developed, rinsed and dried to form a pattern thereon. Then, a process comprising steps of etching the silicon through the pattern, rinsing and drying is carried out to manufacture the above-mentioned device. In the specification, the resist is defined as the polymer material sensitive to light, X-ray, electron beam or the like.
A special-purpose processing apparatus is required in each of these steps. Further, since chemical solutions such as a developer and a rinser have been used in development, rinsing and cleaning processes, a drying step is essential after the rinsing and cleaning steps.
Patent Document 1 discloses a rinsing apparatus for rinsing such micromachined parts as a semiconductor and liquid crystal display where a rinsing medium in the supercritical state is used.
Patent Document 2 shows a method of rinsing with a supercritical fluid in the step of forming a microscopic structure or production of a semiconductor device.
Patent Document 3 describes a drying apparatus using a supercritical fluid in the production of a semiconductor device.
Patent Document 4 indicates a method for forming the pattern of a resist by development using a supercritical fluid.
Patent Documents 1 through 3 disclose rinsing and drying with a supercritical fluid, but fail to show development of the substrate having an exposed resist, using the supercritical fluid.
The present inventors have found out the following problems in the above-mentioned drying process:    (1) The pattern collapse may be caused by the action of surface tension of the above-mentioned chemical solution remaining in the pattern formed in the resist film.    (2) When, in order to prevent the pattern from collapse, a drying method using the supercritical carbon dioxide is used in the drying process for reducing the surface tension acting on the pattern, water remaining in the pattern cannot be completely removed even if the supercritical carbon dioxide is used as the drying agent, subsequent to alkali development and water rinsing. The prior art method cannot prevent the pattern from collapse. For this reason, the present inventors have found it difficult to use the drying method using the above-mentioned supercritical fluid.
The present inventors have also found out the following problems: In the development of the resist film having a microscopic structure with the supercritical fluid as shown in Patent Document 4, carbon dioxide is introduced into the development processing chamber by heating the development processing chamber. As the heat capacity of the chamber becomes larger, the time period for reaching the temperature to the set level, which is above the critical temperature at which the intended dissolution power is exhibited is prolonged. That is, the intended dissolution power becomes equal to the development conditions. This leads to the failure to obtaining a satisfactory result. Especially when a plurality of large-diameter resist films each having a diameter of 200 mm or more are developed, some of the resist films touch the liquid carbon dioxide when it is introduced. This results in phenomena that are beyond the control, thereby causing fluctuations in development.